The basis of all flags of Nordic nations and adopted by the world's 'happiest' country; Denmark
The Dannebrog Cross is similar to the Swiss Cross. But where the white cross on the Swiss flag is couped, the white arms of the Danish cross extend to the edges of the field.
Danne and brog are old Danish words that mean Denmark and cloth. Therefore Dannebrog is the name of the Danish flag.
The Dannebrog Cross is also known as the Nordic Cross and is the basis for all flags in Scandinavia. These include the flags of Finland, Norway, Sweden, Skåneland, Faroe Islands (Denmark), Åland Islands (Finland), plus neighbouring places that are not always considered Scandinavian, such as the Shetland Islands (Scotland), Orkney (Scotland), and Iceland.
Denmark is where Lego comes from (and Danes of course). It is also the happiest place on Earth, according to Science Daily1. The same survey calculated that second happiest is Switzerland, and all Nordic countries are high in the happiness league.
It must be the flag!
1 : University of Leicester (2006, November 14). Psychologist Produces The First-ever 'World Map Of Happiness'. ScienceDaily. Retrieved January 8, 2008, from http://www.sciencedaily.com/releases/2006/11/061113093726.htm